Reduce cardinality of OpenCensus stats (#556)

Co-authored-by: Azeem Shaikh <azeems@google.com>

checker/check_runner.go

@@ -47,8 +47,7 @@ func (l *logger) Logf(s string, f ...interface{}) {
 }
 
 func (r *Runner) Run(ctx context.Context, f CheckFn) CheckResult {
-	ctx, err := tag.New(ctx,
-		tag.Upsert(stats.Repo, r.Repo), tag.Upsert(stats.CheckName, r.CheckName))
+	ctx, err := tag.New(ctx, tag.Upsert(stats.CheckName, r.CheckName))
 	if err != nil {
 		panic(err)
 	}

cron/monitoring/exporter.go

@@ -32,7 +32,7 @@ type exporterType string
 
 const (
 	stackdriverTimeSeriesQuota              = 200
-	timeoutMinutes                          = 10
+	stackdriverTimeoutMinutes               = 10
 	stackDriver                exporterType = "stackdriver"
 	printer                    exporterType = "printer"
 )
@@ -68,7 +68,7 @@ func newStackDriverExporter() (*stackdriver.Exporter, error) {
 		ProjectID:         projectID,
 		MetricPrefix:      "scorecard-cron",
 		MonitoredResource: gcp.Autodetect(),
-		Timeout:           timeoutMinutes * time.Minute,
+		Timeout:           stackdriverTimeoutMinutes * time.Minute,
 		// Stackdriver specific quotas based on https://cloud.google.com/monitoring/quotas
 		// `Time series included in a request`
 		BundleCountThreshold: stackdriverTimeSeriesQuota,

cron/worker/main.go

@@ -157,7 +157,6 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	defer exporter.Flush()
 	defer exporter.StopMetricsExporter()
 
 	checksToRun := checks.AllChecks
@@ -184,6 +183,7 @@ func main() {
 		}
 		// nolint: errcheck // flushes buffer
 		logger.Sync()
+		exporter.Flush()
 		subscriber.Ack()
 	}
 	err = subscriber.Close()

stats/tags.go

@@ -19,8 +19,6 @@ import "go.opencensus.io/tag"
 var (
 	// CheckName is the tag key for the check name.
 	CheckName = tag.MustNewKey("checkName")
-	// Repo is the tag key for the repo name.
-	Repo = tag.MustNewKey("repo")
 	// RequestTag is the tag key for the request type.
 	RequestTag = tag.MustNewKey("requestTag")
 )

stats/views.go

@@ -15,7 +15,6 @@
 package stats
 
 import (
-	"go.opencensus.io/plugin/ochttp"
 	"go.opencensus.io/stats/view"
 	"go.opencensus.io/tag"
 )
@@ -24,11 +23,12 @@ var (
 	// CheckRuntime tracks CPU runtime stats.
 	CheckRuntime = view.View{
 		Name:        "CheckRuntime",
-		Description: "CPU runtime stats per repo per check",
+		Description: "CPU runtime stats per check",
 		Measure:     CPURuntimeInSec,
-		TagKeys:     []tag.Key{Repo, CheckName},
+		TagKeys:     []tag.Key{CheckName},
 		//nolint:gomnd
 		Aggregation: view.Distribution(
+			0,
 			1<<2,
 			1<<3,
 			1<<4,
@@ -42,16 +42,15 @@ var (
 			1<<12,
 			1<<13,
 			1<<14,
-			1<<15,
-			1<<16),
+			1<<15),
 	}
 
 	// OutgoingHTTPRequests tracks HTTPRequests made.
 	OutgoingHTTPRequests = view.View{
 		Name:        "OutgoingHTTPRequests",
-		Description: "HTTPRequests made per repo per check per URL path",
+		Description: "HTTPRequests made per check",
 		Measure:     HTTPRequests,
-		TagKeys:     []tag.Key{Repo, CheckName, ochttp.KeyClientPath, RequestTag},
+		TagKeys:     []tag.Key{CheckName, RequestTag},
 		Aggregation: view.Count(),
 	}
 )